FR2608642A1 - METHOD AND DEVICE FOR MANUFACTURING REINFORCED WIRE - Google Patents

Abstract

PROCESS FOR MANUFACTURING A REINFORCED WIRE CONSISTING OF SENDING THE REINFORCING FIBERS ON THE DISC 8 OF THE TORSION UNIT 7, THROUGH THE DISC 8 THROUGH THE BLIND WIRE 19 ECCENTRICALLY WITH RESPECT TO THE ROTATION AXIS OF TORSIONING UNIT 7 AND COVERING THE CORE WIRE 19 WITH THE FIBERS TO THUS FORM A REINFORCED WIRE 15 BY ROTATING THE TORSIONING UNIT 7. MANUFACTURE OF LOW-TENSION REINFORCED WIRES.

Description

The invention relates to textile industry, especially spinning and more

especially to the proccesses

  and devices for making a reinforced wire.

  A reinforced yarn is a yarn covered over its entire length - of fibers or other yarns, the coated yarn being called core yarn and the fibers or yarns that are wound

  around the soul thread Etan; called recovery components.

  The use of renamed yarns is becoming more and more important because they offer a series of advantages over a single yarn, the most important of which is the ability to combine the properties of materials in different ways. core wire and overlap components, which allows to obtain any properties, for example, toughness, hygroscopicity,

the crease resistance of the finished product.

  Various methods of manufacturing reinforced yarns using fiber-covering components are known. Among these methods are pneumomechanical spinning or "free-end" spinning in which the fibers intended to be wound around the core wire are obtained by dissociation of a fiber ribbon in a dispersion or shredding device, while the core wire is covered with fibers wrapped around it by means of a torsion member, usually used for pneumomechanical spinning and made either in the form of a bowl called a "spinning chamber" or in the form of a T-shaped disk on its rotating shaft, or in the form of another known type. for example in the form of a funnel (US Patent No. 3,605,395); on the other hand, since, in any type of torsion member, the core wire, to be covered with fibers, must pass through the rotational shaft of the torsion member, these shaft

must be hollow.

  Thus, to obtain a reinforced yarn, any method and device used for pneumomechanical spinning may be used with a so-called "direct current" spinning system, ie a system where individualized fibers are sent to the torsion member at one of its ends and the produced wire is taken out of the hollow shaft at its other end

  (U.S. Patent Nos. 3,411,283 and 3,501,905).

  However, when twisting members in the form of a bowl (spinning chamber) or disc are used to obtain a reinforced wire, problems arise. For example, when using a threading chamber there is a quality problem of the thread manufactured, because, in this case, the density of recovery of the core wire by the fibers depends on their tension, due solely to centrifugal forces. which, for the actual rotational speeds of the spinning chamber, are insufficient to ensure the strength of the cover. If a disk-shaped torsion member is used, there is a problem of reducing the projection of the fibers of the disc surface under the action of the centrifugal forces, which can only be overcome by either maintaining in a safe manner the fibers on the surface of the disk until they are taken and twisted by the core wire, either by ensuring the engagement and attachment by the core wire of a maximum quantity

  of fibers arriving before the centrifugal forces begin

cent to act on these fibers.

  The method and the device of the invention are more particularly oriented towards solving this problem.

  last problem. A pneumatic spinning process is known

  mechanical (German Patent No. 1,560,313) using a device comprising as torsion member a T-shaped perforated disk with an axial passageway through which the fibers pass and provided with vanes fixed under the disk and forming a fan-finned wheel creating a flow of air passing through the perforations of the disc to convey and retain on the surface of the disc

individual fibers.

  It is known that most fibers can be electrified by their friction against each other during their movement. The method and the pneumomechanical spinning device are based on this property of the fibers and are characterized. in that, to clamp and retain the fibers on the surface of the disk, an electrostatic field is created between a fixed electrode, disposed at the end of the fiber-guide channel, and the disk, which constitutes the second electrode. Thus, the fibers are tight and held on the surface of the disc by means of a

  electric discharge by Corona effect and an air flow.

  However, the efforts retaining the fibers according to this process have limit values, which are sufficient only at low speeds of the torsion member, since the increase of the intensity of the electrostatic field above a certain value is inadmissible for

  reasons of safety, and the retention of fibers by suction

  The airflow through the perforations is inefficient because the lower fiber layer on the surface of the disk seals the perforations and

  do not allow adequate confinement of the upper layers

  fiber, on which the sucked air has only a very weak action. Also, when the rotation speed

  of the torsion member increases and that the centric forces

  fuges grow, the upper layers of fibers are projected out of the disc, giving a thread of poor quality. Moreover, the down that contains the fiber and the various impurities accumulate gradually in the perforations by closing them and the aspiration of the air through the perforations stops and the fibers are no longer retained on the surface of the disc , which disrupts the spinning and causes the stop of the torsion member for cleaning. The peculiarities of the known method and devices limit the increase in the rotational speed of the torsion member and, consequently, the efficiency

  spinning machines operating according to this method.

  Another method and apparatus for obtaining a reinforced yarn is known (see U.S. Patent No. 3,877,211), which for the most part is analogous to the foregoing method and apparatus, but different in that the separated fibers are retained at the same time. disc surface by mechanical means, which are projections uniformly distributed over a circumference at the surface of the disc, at a distance from the axis of rotation of the torsion member, and in that, for the passage of the current of air, in the body of the disk are formed radial slots uniformly distributed around the periphery of the latter, the interval

  between two adjacent slits having at least one of said projections.

  These projections form on the surface of the disc a rim capable of accumulating and retaining the main flow of fibers on the central part of the disc, which allows the core wire to be covered at high speeds. This is possible by the fact that at speeds

  torsion organ, when the centric forces

  fuges grow, rejecting the fibers of the disk surface, the mechanical action of the projections prevents this rejection. The

  radial slots provided on the disc not only allow-

  the passage of the air stream through the disk by bringing the separated fibers to the surface of the disk, but do not prevent the free passage through the disk of the down contained in the fiber nor impurities, which ensures operation extended torsion member without it being down and without being engorged so

necessary to clean it.

  However, the methods and means described above for retaining the fibers on the surface of the disc are insufficiently effective since they are only intended to counteract the effect of the centrifugal forces acting on the fibers on the surface of the disc and do not exclude the action of centrifugal forces on the separated fibers during their setting and driving by the core wire before these fibers come into contact with the surface of the disk, that is to say, before the beginning of the action of centrifugal forces on the fibers. This is why the percentage of fiber losses from the surface of the disk remains high and compared to the volume of the fibers sent to the surface of the disk, reaches 10-12%, for light natural fibers, and up to 20%. % for fibers

heavy synthetics.

  The problem indicated is solved in part by the method of manufacturing a reinforced wire (German Patent Application No. 36 12 667.5 of 15.04.86) by pneumomechanical spinning, which consists in sending a stream of separated fibers to the flat surface of the disk. of the twisting member rotating, passing the core wire through this disk and winding fibers around the core wire forming a wire reinforced by rotation of the torsion member. This method is characterized in that is passed through the torsion member and through the disc at least two core son disposed at an angle relative to each other. The core threads then form in the path of the separated fibers a kind of wedge into which the introduced fibers penetrate. Due to the axial longitudinal movement of the core wires and their connection in the axial opening of the disk, these fibers are pinched between the two core wires and no longer reach the surface of the disk, but are driven by the core wires in its axial opening, where the centrifugal forces are practically absent and the ends of these fibers are twisted around the core wires. Thus the separated fibers taken between the core wires remain outside the zone of action of the centrifugal forces which reduces the losses of fibers and the quantity of waste and increases the quantity of reinforced wire of good quality and the efficiency of the machines . The effect indicated increases noticeably when the number of core threads is increased, because the higher the number of core threads, the greater the number of "corners", that is, the larger the pinch areas. many fibers, the higher the amount of fiber outside

  the zone of action of the centrifugal forces.

  Also known is a device for manufacturing a reinforced wire (German Patent Application No. 36 61 667.5 of 15.04.86), comprising a device for separating the fibers, a torsion member with a flat disk, connected to a fiber-guide channel and to the axially open fiber dissociation device with means for retaining the fibers and radial slots for passage of the air flow created by fins radially fixed on the body of the torsion member and on the surface of the flat disk and oriented towards the body of the torsion member, a coil carrier with a core wire coil, a winding assembly of the finished reinforced wire and a wire guide

  of soul disposed above the plane of the device.

  The peculiarity of this device is that in addition to the main guide of the core wire, in the form of said opening made in the body of the device and offset from the axial opening in the disc, guides additional are provided, according to the number of core son, also made in the form of openings in the body of the device, offset with respect to the axial opening of the disc. These openings in the body of the dispsotif are arranged relative to each other so that two neighboring core wires, passing through these openings towards the axial opening of the disk, form between them an angle whose apex is inlet of the axial opening, which allows the separated fibers brought into this angle to be pinched by the core threads being scrolled and thereby to exclude

  the action of centrifugal forces on these fibers.

  The description of the thread interaction process

  With the fibers separated in the known process, it is easy to establish that the smaller the angle of the wedge formed by the core wires, the better the conditions for them to grip the fibers, since when the angle soul threads are weak, they get closer to each other before joining them in the axial opening of the disc. This increases the fiber gripping zone by the core yarns and their gripping power, which also reduces the probability of falling or rejecting the fibers present in the corner during the movement of the core threads or under

the action of the air stream.

  However, if the opening angle between the core wires is small, the surface they intersect in the path of the individualized fiber stream, which constitutes the possible fiber engagement area by the core wires, does not represents a small portion of the total area of the section of the fiber stream, because the fibers are uniformly sent over the entire fiber receiving surface of the disk, between the projections. Since only a small part of the total volume of the fibers sent can be taken by the core threads, most of the fibers are outside the action zone of the "wedge" formed by the core threads and reaches the surface of the disc, where it

  is subjected to the action of centrifugal forces.

  This is why the effect of reducing the fiber losses of the surface of the disc, according to this process does not reach a significant value and does not exceed in practice 1 to 2% for natural fibers and 0.5 to 1, 5% for

smooth synthetic fibers.

  On the other hand to achieve this process and achieve the desired effect there must be at least two son of soul. This means that, according to this method, it is only possible to manufacture threads reinforced with headlines. When the technology requires fine titles of reinforced yarns or if the required properties of the finished yarn require only one core yarn, such reinforced yarn can not be produced by this process, which limits the range of reinforced yarns obtained

  according to this method and this device.

  The aim of the invention is to provide a method and a device for manufacturing reinforced yarn capable of taking up and interlocking with a single core yarn the maximum of fibers sent onto the receiving surface of the fibers of the disc, and this before the fibers touch this surface and undergo the action of centrifugal forces, which ensures a significant reduction in fiber losses, the amount of waste, and improves the percentage of defined reinforced wire of good quality, while allowing

  to expand the range of reinforced yarns manufactured.

  The essence of the invention is that in the method of manufacturing a pneumomechanically-spun-reinforced yarn of the invention, a flow of dissociated fibers is sent to the flat surface of the disc of a rotating twister, a core wire is passed through the disc of the torsion member, the covering fibers are wound on the core wire, and a reinforced wire is formed by rotating the torsion member, the wire

  of soul passing through the disk of the eccentric torsion member

  relative to the axis of rotation of the torsion member, to form the core wire according to two plies situated on opposite sides of the disk when the torsion member rotates, the vertices or nodes of the plies lying on

  the axis of rotation of the torsion member.

  The device according to the invention for obtaining a reinforced wire comprises a device for dissociating the fibers, a torsion member, a flat disc traversed by an axial opening connected by a fiber-guide channel to a fiber-dissociation device, having a means for retaining the fibers and radially arranged slots for the passage of an air stream created by radially fixed fins on the body of the torsion member, a

  core wire feeder, a set of windings

  the guide wire of the core wire disposed above the plane of the disc, the disc having an eccentric opening relative to the axis of rotation of the torsion member, for the passage of the wire of soul, the geometric axis of the guide of the core wire being disposed on the axis

of rotation of the torsion member.

  The invention improves the efficiency of the spinning and coating machines and allows the range of

  tissues with various properties.

  The process of the invention is carried out in the manner

next.

  A nonwoven fiber ribbon is dissociated into individualized fibers in a fiber dissociation device. The flow of dissociated fibers obtained is sent onto the flat surface of the rotating disc of the torsion member. The core wire is unwound from a supply reel and is first passed through the guide, whose geometric center is disposed on the axis of

  rotation of the torsion member, then it is made

  the disc, eccentrically with respect to this axis, after which it is passed through the axial channel of the torsion member. Then, by rotating the torsion member, the fiber core wire is wrapped around

  thereby forming a reinforced wire.

  The principle of pneumomechanical spinning is as follows. When the core wire is covered with fibers, which on the surface of the disk are oriented mainly in the radial direction relative to the axis of the disk, thanks to the presence of the radial slots in the disk, the setting of the fibers by the core wire and their winding on it occurs first by the ends of those of the fibers which are located near the core wire and come into contact with this core wire. Then, at the free ends of the entangled fibers which move on the surface of the disk, attach other fibers further from the core wire,

  and so, on the surface of the disc during the

  there is always, turning around the core wire, the end of a bundle of fibers wound on the core wire (so-called "open end"), to which are attached, then s 'wrap around the soul thread,

  new portions of individualized fibers brought.

  When the disk rotates with the core wire about the axis of the torsion member, the core wire moves in two layers: the upper web above the disk and the lower web below the web. disk. The vertices or nodes of the plies are located on the axis of rotation of the torsion member, the top of the upper ply, by centering on the axis of rotation the guide of the core wire, and the top of the ply. lower, driving the finished reinforced wire into the axial channel of the torsion member for

  then evacuate through this channel.

  The effect of reducing fiber losses obtained by the process described above is explained by the fact that the upper sheet formed by the core wire, passes at a high frequency the flow of free fibers to the central portion of the disk. The core wire then engages, at a high speed, in the flow of fibers and encounters in this stream individualized fibers, this encounter of the core wire with the individualized fibers representing a shock ii under the effect of which the Fiber is folded and comes to hug around the soul wire. Thus, a large part of the fibers is already entwined in flight around the core wire, when it meets the approaching the surface of the disc. Thanks to a known property of cohesion of the fibers with one another, other fibers which have not come into direct contact with the core wire can attach themselves to these fibers which have already done so which increases the total amount of

  fibers clinging to the core wire before reaching the disc.

  If the web of the core wire passes through the entire section of the fiber flow, the core wire ensures in this case the setting and the interlacing in flight of a maximum quantity of the fibers fed over the entire receiving surface of the disk. . Since we can vary the height and the diameter at will

  of the web traversed by the soul thread by modifying the excen-

  of the passage opening in the disk and the position of the guide, it is possible to adjust the area of the cross-section of the flux of flux fibers that is interested by the web of the core wire, that is to say the zone of action of this web in the fiber stream and, therefore, choose optimal values depending on the type of fiber used and the

  properties of the reinforced wire to obtain.

  The part of the fibers, which reaches the surface of the disc and moves on the latter under the action of the centrifugal forces from the center to the periphery, also meets on its path the web of the core wire, which holds in the winding around him, the fibers as if they floated in the air, also the losses

of fibers decrease.

  The part of the fibers, which, under the action of the air flow, passes through the axial opening of the disc meets on the other side of the latter the lower sheet of the core wire, which intercepts the fibers just as the upper layer. Thus the free fibers are subjected several times in their path to the torsion member and in the latter to the action of the webs formed by the core wire, which captures and embraces them, and the losses in fibers to from the disc surface of the torsion member are significantly reduced, about 5 to 6 times, and reach

  in practice only 2 to 3% at most.

  For example, in the manufacture of a 250 tex reinforced yarn with a linear density polyester yarn "lavsan" of linear density 111 tex coated with short cotton fibers, the rotational speed of the torsion member reaching 30,000 rpm and speed of wire making, 60 m / min, fiber losses from the surface

  of the disc were equal to 2.6%.

  The features of the invention stand out

  more particularly from the following description made in

  with reference to the accompanying drawings, which represent: FIG. 1, the block diagram of the device for manufacturing a reinforced wire, according to the invention; - Figure 2, the disc of the torsion member, in perspective, partially cut away, according to the invention; - Figure 3, schematically, the two layers

  reinforcing core wire according to the invention.

  The device for manufacturing a reinforced yarn comprises a device for separating the fibers which comprises a guide and densification chute

  (condensation) 1 (Figure 1) feeding a couple of

  consisting of a feed roller 2 and a

  shelf spring 3, pressed against the roller 2, the end

  1 of the chute 1 located at the inlet of the feed torque, a shredding roller 4 disposed in the

  body of the device; this body includes a guide channel

  fibers 5 having a lateral opening 6.

  The device of the invention comprises a torsion member 7 of the wire to be reinforced consisting of a perforated flat disk S which has a hole 9 arranged on its upper surface with a means for retaining the fibers, produced according to the described variant. in the form of these protrusions SC regularly distributed, crossed racial slots A ensuring the passage of a current c'air created by the

  radial fins 12 of a centrifugal fan.

  In the modified variant 1, the fins 2 are fixed at the end on the cylindrical body 13 which the torsion orcane and carry the disc 8, the projections 10, alternating regularly with the slots 1-1, are substantially of conical shape with a vertex arronc :, the slots it goes jusou'à

the periphery of the discus 8.

  In the cylindrical body 13 there is an axial channel 14 for evacuating the reinforced wire 15 to a winding assembly, comprising a friction lug 16 and a

coil 17.

  In the disk 8 is made an opening 18 eccentric with respect to the axis of rotation of the disk 8, for the passage of a core wire 2.9 unrolled from a bin 20, fixed on a support, through a cuide- 21 and a flange 22 disposed in the opening 6 of the channel 5 so that its geometric center is on the axis of rotation of the torsion member 7. The torsion orcane 7 is mounted in bearings to bearing 23 and is driven by a

  control 24 for example belt.

  A fiber ribbon 25 placed in a pot 26 and extracted at

using a roller 27.

  FIG. 3 diagrammatically represents the two plies 28, 29 of the core wire 19 with their vertices or nodes.

and 31 respectively.

  The device operates as follows.

  The fiber ribbon 25 (FIG. 1) is sent from the pot 26 by means of the roller 27 into the condensation chute 1, where the ribbon is condensed and rectified. On leaving the chute 1, the condensed ribbon 1 arrives at the feed torque, which sends it to the shredding roller 4. The shredder roller dissociates the fibers from the ribbon 25, which are detached from the teeth of the roller 4 by a stream of air and sent by the fiber-guide channel 5 to the torsion member 7. The air stream bringing the fibers separated by the channel 5 is formed, during the rotation of

  the torsion member 7, thanks to the fins 12 of the fan.

  The separated fibers are sent to the surface of the flat disk 8, where, thanks to the distribution of the air flow by the radial slots 11, they are mainly oriented in the radial direction and arranged between the conical projections 10, which serve to retain fibers. The core thread 19 unwound from the spool 20 passes through the guide wire 21 and the guide 22, whose geometric center is disposed on the axis of rotation of the torsion member 7, then passes through the opening 18 and then through the axial channel 14. When the torsion member 7 rotates, the core wire 19 forms in the path of the fiber stream shaped by the channel 5 two layers, upper with its top in the eye of the 22, and lower, with its apex in the axial channel 14. During the high-speed meeting of the fibers with the core wire, the fibers are taken and nested by twisting as shown in Figure 2. A these fibers are located on the surface of the disk 8 are attached other fibers located between the projections 10 and partly in the radial slots 11, resulting in the formation of a reinforced wire

  , which is evacuated through the axial channel 14 to the assembly

  winding wire and wound by means of the friction shaft

16 on the spool 17.

  The possibility of using a single core wire of any linear density and with any kind of fibers according to the method of the invention makes it possible to manufacture a wide range of reinforced and coarse yarns.

  -35 cubic meters with low fiber consumption.

  Thus, the method and the device of the invention for the manufacture of a reinforced wire ensure a significant reduction in fiber losses, the amount of waste, while increasing the amount of reinforced wire of good quality and allowing expand the range of wires

reinforced manufactured.

Claims (2)

- CLAIMS -   1. A method of manufacturing reinforced thread by pneumomechanical spinning o: - a flow of fibers is sent on the upper flat surface of the disc (8) of a rotating torsion member (7); - The core wire (19) passes through the disc (8) of the torsion member (7); - the core wire (19) is covered with fibers, to form a reinforced wire (15) by rotating the torsion member (7); characterized in that the core wire (19) passes through the disc (8) of the torsion member (7) eccentrically with respect to the axis of rotation of the torsion member (7) to form during of the rotation of the torsion member (7), two webs (28, 29) of the core wire, located on opposite sides of the disk (8), the vertices or nodes (30, 31) of the webs (28, 29); ) being arranged on the axis of rotation of the torsion member (7). 2. Device for carrying out the method according to claim 1, comprising a device for dissociating the fibers; a torsion member (7) comprising a flat disk (8) pierced with an axial orifice (9) connected by a fiber-guide channel (5) to the device for dissociating the fibers, provided with means for retaining the fibers and having radial slots (11) for the passage of a stream of air created by fins (12), radially fixed on the body (13) of the torsion member (7) and on the surface of the flat disk (8) facing the body (13) of the torsion member (7); a coil carrier (20) delivering the core wire (19), a winding assembly of the reinforced wire; a guide (22) of the core wire disposed above the plane of the disk (8), characterized in that in the plane of the disk (8) is provided an opening (18) for the passage of the wire of core (19), eccentric to the axis of rotation of the torsion member (7), the geometric center of the guide (22) of the core wire being   on the axis of rotation of the torsion member (7).